public class DiGui2 {
	
	// 5 * 4 * 3 * 2 * 1
	public static void main (String[] args) {
		
		int retVal = dg(5);
		U.p(retVal);
	}
	
	public static int dg(int a) {
		
		if (a == 1) {
			return 1;
		}
		return a * dg(a - 1);
		
	}
	
}